1. Field of the Invention
This invention relates in general to iron golf club heads, and more particularly to an iron club head having a club face and related portions made from a fiber reinforced synthetic resin.
2. Description of the Prior Art
Recently, an iron club head of the type having a club face and related portions made from a synthetic resin reinforced with non-metallic fiber, such as carbon and glass or the like, has been developed, as shown in, for example, Japanese Utilization Publication No. 17883/1978 or Japanese Utilization Laid-Open No. 16670/1984. The above iron club head comprises a sole portion and adjacent to it a hosel portion, both of which are made from stainless steel or other metal, and a metallic core material of plate-like or other form is disposed vertically so as to make the sole portion an integral part thereof; the core material portion being formed integrally with the fiber reinforced synthetic resin which forms the club face portion of the club head, the toe portion, the top portion and the back portion.
Such a club head has superior impact resilience thanks to its fiber reinforced synthetic resin and this superior impact resilience lengthens the ball driving distance, while at the same ensuring that the impact at the time of hitting a ball is as soft as that experienced with a wooden club and that ball control is easy. As a result, direction control is easier than it is with an iron club made only from metal.
There is, however, a problem with the above iron club in that the surface of the synthetic resin tends to be easily worn and broken because the carbon fiber or glass fiber is mainly used as a reinforcing fiber for the synthetic resin which forms the club face and related portions of the iron club head; that is, the surface of the club face of the club head wears and dents to form a crater after it has been used repeatedly to hit balls. These dents lead to a loss of ball control. Another problem is a failure to produce back spin because of the slippage which occurs on impact causing the ball to stop at the target point is a case where the scoring lines cut on the surface of the club face disappear. Particularly in the case of a short iron club which tends to be used with a high degree of back spin and in locations where there is much earth and sand, wear of the surface of the club face increases even further. When the club head is driven into sand on a fairway bunker when attempting to hit a ball, or when a ball is hit in an overgrown place such as the "rough", a groove portion forming the scoring lines on the surface of the club face and a hem portion of the club head are liable to be broken, or the surface of the club face may be easily damaged if the club head unintentionally hits or touches a stone or rock or the like in the sand or the "rough". Furthermore the impact which occurs when club heads strike each other during storage in golfbag or during transport can lead, for example, to the top portion, the toe portion and related portions thereof being damaged.
An object of the present invention is to provide an iron golf club head which is capable of overcoming the above problems, wherein wear resistance of the surface of the club face, which is made of synthetic resin, is improved and the surface is made to be such that it will be resistant to breakage.